Crohn’s disease is one of the two main forms of inflammatory bowel disease – the other is ulcerative colitis.

What is Crohn’s disease?

Crohn’s disease is a condition that can cause inflammation at any point along the digestive tract, from the mouth to the anus, although it is most commonly seen around the junction of the small intestine and the large intestine.

It may only affect a small part of the bowel or multiple sections may become inflamed at the same time.

There is no know cure, and even if infected sections of the gut are removed, the disease will invariably return. However, the symptoms may stay in remission for many months, or even years at a time between flare-ups.

What causes Crohn’s disease?

Crohn’s disease is thought to be caused by a faulty reaction in the immune system to bacteria in the gut, although why this happens, and which bacteria are involved is not yet fully understood.

There is good evidence that Crohn’s has a genetic component, although previous intestinal infections may also play a part. Since Crohn’s is less common in the poorest parts of the world, some people suspect that overprotected Western children are not being exposed to enough germs to develop the correct immune responses.

Symptoms of Crohn’s disease

The symptoms of Crohn’s disease are similar to ulcerative colitis, and include:

  • Diarrhoea
  • Abdominal pain
  • Fatigue
  • Weight loss
  • Blood and mucus in the stool

The symptoms will vary depending on where the flare-up occurs, and the severity of the inflammation.

Diagnosing Crohn’s disease

Diagnosis of Crohn’s disease relies combined evidence from endoscopy, histology and CT or MRI scanning. Initial investigations include blood tests and endoscopic investigations, which usually include colonoscopy and/or endoscopy of the stomach (OGD).

Small bowel Crohn’s disease is diagnosed using either specialist small bowel ultrasound or MRI enterography to avoid the risks of excessive radiation exposure. Dr Ana Wilson works closely with leading specialist gastrointestinal radiologists in London to achieve the most accurate diagnosis for her patients.

Treating Crohn’s disease

Find out more about how Crohn’s disease is treated.

Complications of Crohn’s disease

The main complications of Crohn’s disease are stricture and fistula formation.

  • Bowel strictures occur as a result of progressive inflammation and they can lead to a complete bowel blockage.  If strictures become chronic the patient may need surgery to clear the blockage, either by reopening the passageway or removing the infected section of bowel. However it may be possible to reopen the stricture endoscopically from inside the bowel with an interventional therapeutic colonoscopy.
  • A fistula is an abnormal communication channel between one loop of bowel and another abdominal organ (which may be another loop of bowel, bladder or even skin).  These can allow faecal matter to leak into the abdomen causing serious problems. Management of fistulae depends on their location but usually involves a combination of strong medical treatments, such as biologics, and surgery.